Heating, ventilation, and/or air conditioning (HVAC) systems are often used to control the comfort level within a building or other structure. Such HVAC systems typically include an HVAC controller that controls various HVAC components of the HVAC system in order to control one or more environmental conditions within the building. In some cases, it may be desirable for a user to be able to affect the operation of an HVAC system from a remote location. In such cases, communication between a user's remote device and the HVAC controller located within a building may be routed through a web server or the like to which both the user's remote device and the HVAC controller are connected. What would be desirable are methods and systems for improving the reliability and/or user experience of such a system, particularly when the HVAC controller is powered by a local power source such as a battery.